Siphon



United States Patent Ofilice ifihhfillhil Patented Feb. 28, 1967 3,306,060 SIIPHON Gustav Klipping, Berlin-Zehlendorf, Germany, assignor to lvlax-Planck-Gesellschaft zur Fiirderung der Wissenschaften e.V., Gottingen, Germany Filed May 14, E65, Ser. No. 455,687 Claims priority, application Germany, May 14, B64, M 60,998 6 Claims. (Cl. 6255) The present invention relates to a siphon for transferring low-temperature-boiling gases that are in the liquid phase from a supply reservoir to a working container, and more particularly to such a siphon which is equipped with a shut-off valve. The riser tube of the siphon extends into the supply reservoir and can be closed ofi by valve means located at the top end of a control sleeve which can be moved vertically by means of a ring on its lower end, which ring rides in a threadedly mounted guide sleeve. Rotation of the guide sleeve moves the ring, controlling the valve. The guide sleeve is provided in a housing and is sealed off from the atmosphere by bellows elements.

Liquid refrigerants which have low boiling points, such as nitrogen, hydrogen, and helium, are stored in vacuuminsulated containers, from which they are removed by means of vacuum jaket siphons. When handling helium and hydrogen it has proven practical to insert a vacuum jacket siphon into the supply reservoir, which siphon has a shut-off valve that is then located in the neck of the reservoir, and to couple the siphons of individual working containers to said valved siphon.

In order to keep the heat flow to the inner container of the supply reservoir as low as possible, the neck of the supply reservoir is kept as narrow as possible, generally about 14 mm. in diameter. Within this tube, in the case of the coupled siphon, five tubes have to be placed inside of each other. These tubes are: the vacuum jacket tube, the inner tube or channel of the siphon in which the shut-off valve is located, the guide sleeve for the valve element, and the inner tube and vacuum jacket tube of the coupleddn siphon. The guide sleeve must be capable of moving together with the valve element. The siphon which is attached to the working container consequently has to have a small diameter, and furthermore to have thin walls, in order to keep the heat flow across the junction point of the siphons small. This siphon is consequently very sensitive to mechanical stresses. In continuous flow cryostats, for which this kind of coupling siphon is of special interest, the siphon that has to be coupled in is joined directly to the cryostat. When assembling and rebuilding installations in which the continuous ilow cryostat is permanently installed as part of a large system, there is a constant danger of damaging the sensitive siphon socket. A further disadvantage of conventional devices lies in that the siphon valve, located in the neck of the supply reservoir, is liable to tilt due to the inevitably present small valve clearance. Furthermore, the valve seat is accessible for repair only with difliculty.

It is therefore an object of the present invention to provide a vacuum jacket siphon which overcomes these defects of the prior art.

It is a further object of the present invention to provide a vacuum jacket siphon having an easily acessible shutoff valve, the riser tube of which siphon extends into the neck of the supply reservoir.

These objects as well as others are achieved acording to the invention wherein a vacuum jacket siphon is provided for transferring low-boiling-point liquids from a supply reservoir to a working container, which siphon includes a siphon housing, including means for coupling the housing to a supply reservoir, riser tube means extending from the housing beyond the coupling and insertable into the supply reservoir to receive the contents thereof, a valve on the top end of the riser tube, means for regulating the flow through the riser tube, valve control means fastened to the valve and extending back along the riser tube to the housing and a guide sleeve in the housing for actuating the control means to control the valve means. The riser tube of the siphon extends into the supply reservoir and can be closed off by valve means located at the top end of a control sleeve which can be moved vertically by means of a ring on its lower end, which ring rides in a threadedly mounted guide sleeve. Rotation of the guide sleeve moves the ring, controlling the valve. The guide sleeve is provided in a housing, and is sealed off from the atmosphere by bellows elements.

Additional objects and advantages of the present invention will become apparent upon consideration of the following description when taken in conjunction with the accompanying drawings in which:

FIGURE 1 shows a cross section of a siphon with a shut-oil valve at its upper end, which siphon is coupled into a continuous flow cryostat.

FIGURE 2 shows an enlarged section of FIGURE 1, the cross section of the shut-off valve.

The siphon shown in FIGURE 1 includes a riser tube 1 for the liquid refri erant, which tube is surrounded by a jacket 2. The jacket 2 is led through a housing 3 in which perforations 23 have been provided, and which has a shut-01f valve 4, through which the space between the jacket 2 and the riser tube 1 can be evacuated. Below the housing portion 3, the jacket 2 has a ring-shaped collar 5 which can be inserted into a matching collar 7, with which it forms an air tight seal. The collar 7 has a lower flange 6 by means of which it can be connected to a supply reservoir (not shown). On the upper end of the siphon, an element 8, designed as a valve seat, locates the riser tube 1 within the jacket 2.

To housing section 3 is soldered a lower bellows 9, the free end of which is soldered into a ring element 10, the opposite side of which is attached to an upper bellows 11. This upper bellows is soldered to the cover plate 12, which is firmly attached within housing section 3. The ring it} is movably guided within a guide sleeve 13. The guide sleeve 13 is threadedly mounted in the housing 3 so that it can move up and down as it is rotated. A tubular control sleeve 14, which surrounds the jacket tube 2 of the siphon, is soldered to ring 10 and carries the valve body 15 at its upper end. By rotary movement of guide sleeve 13, which is accessible from outside the device thrpugh perforations 23 in the housing 3, the ring 10 can be slid, within limits, in two directions along the siphon axis to open and close the valve 8, 15. The inner space between the jacket 2 and sleeve 14 is air-tightly sealed oil from the outer portion of the housing 3, which is filled with air, by means of bellows 9 and 11. On its upper end the housing portion 3 has a ring-type screw joint 16, by means of which a working container, in this case a continuous flow cryostat, can be gas-tightly coupled to the siphon.

The continuous flow cryostat is described here only insofar as it is of interest to explain the sip-hon. The continuous flow cryostat includes a cooling chamber 17 which is provided with fiow slots for the liquid refrigerant, which cooling chamber is located in a housing 18 that can be evacuated. The cold gas that accumulates, during operation, in the fiow system of the cooling chamber 17 is led into an exhaust pipe 19, which forms a spiral cooling tube around the radiation shield 20 before it leaves the housing 18 through flange 21. This flange serves to couple the unit to a control valve and vacuum pump (not shown). According to the arrangement of the siphon coupling herein described, in addition to the cooling of the radiation shield 20 by the cold exhaust gas, it is also possible to cool the inner tube 22, which encloses the siphon with the shut-off valve. This is accomplished by leading the exhaust gas pipe 19 from the cooling chamber 17, within the radiation shield 20, to the inlet region of the inner tube 22, and winding it from there around tube 22 before wrapping it about radiation shield 20. As the annular spaces between the inner tube 22 of the cryostat and sleeve 14, on the one hand, and sleeve 14 and vacuum jacket 2 on the other, are filled with gas, good heat conduction between the tubes is obtained. Therefore the cooling effect of coils 19 is transmitted to the tubes, greatly decreasing heat conduction to the valve 8, 15.

FIGURE 2 shows the shut-off valve 8, 15 in closed position. The upper cylindrical section of valve element 15 is connected to control sleeve 14, whereas the lower conical section of valve element 15 fits into valve seat 8. In open position valve element 15 is lifted from valve seat 8 and the refrigerant flows from riser tube 1 through valve seat 8 and through bores 24 and 25 in valve element 15.

The device described above has several advantages over prior art units. The sensitive siphon socket, which is inserted into the coupling, is here located on the supply reservoir-a position in which it can be much better protected during use. This means that the dimensions of the socket, which extends from the supply reservoir, no longer depend on those of the neck of the reservoir; a larger diameter can be chosen for the socket and greater clearance can be provided for the guide tube of the valve, which improves valve operation. The valve seat is furthermore easily accessible in this device. The proposed siphon also functions better in that it reduces heat flow to the inner container of the supply reservoir. This is because in the instant device, only the riser tube and vacuum jacket tube extend into the supply reservoir. The coupling part of the working container no longer needs to be in the form of a vacuum jacket siphon, but the socket on the supply reservoir, with the shutofi valve, is coupled into a thin-walled guide tube which may be surrounded by any form of vacuum container.

The vacuum jacket is thus, according to the present invention, a part of the vacuum housing of the apparatus that has to be placed on the supply reservoir. This allows the guide tube which encases the siphon jacket, leading to the working chamber, to be cooled, thereby greatly reducing heat flow to the valve.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

What is claimed is:

1. A vacuum jacket siphon for transferring low-boiling-point liquids from a supply reservoir to a working container, said siphon comprising, in combination:

means forming a siphon housing, including means for coupling the housing to such supply reservoir;

riser tube means extending from said housing beyond both ends of the coupling means, one end of the riser tube means being insertable into such supply reservoir to receive the contents thereof while the other free end extends outside of the neck of the supply reservoir;

valve means on the free end of said riser tube means for regulating the flow of said contents therethrough;

valve control means fastened to said valve means and extending along the free end of the riser tube means into the housing; and

guide means in said housing for actuating said control means to control the valve means.

2. A siphon as defined in claim 1, wherein said control means is a control sleeve surrounding the riser tube means and extending from said valve means into the housing.

3. A vacuum jacket siphon for transferring low-boiling-point liquids from a supply reservoir to a working container, said siphon comprising, in combination:

means forming a siphon housing, including means for coupling the housing to such supply reservoir;

riser tube means extending from said housing beyond the coupling means and insertable into such supply reservoir to receive the contents thereof; valve means on the end of said riser tube means for regulating the flow of said contents therethrough;

valve control means fastened to said valve means and extending along the riser tube means into the housing, said control means being a control sleeve surrounding the riser tube means and extending from said valve means into the housing;

guide means in said housing for actuating said control means to control the valve means, said guide means including a longitudinally disposed guide sleeve threadedly engaged in said housing so as to move longitudinally when rotated and engaged with said control sleeve; and

means for sealing off the interior of said control sleeve from the atmosphere, said control sleeve terminating within said housing in a ring element, said guide sleeve having an interior groove for slidably retaining said ring element; said sealing means including a pair of tubular bellows extending longitudinally in opposite directions from the ring element and affixed at their respective other ends to said housing.

4. A siphon as defined in claim 3, wherein said riser tube means includes a central riser tube through which contents flow and a vacuum jacket surrounding the riser tube, the free end of said riser tube means forming a valve seat constituting a part of said valve means, said valve means also including a valve element attached to the control sleeve for cooperating with said valve seat to control the flow through the riser tube.

5. A device as defined in claim 4-, wherein said housing is slotted in the region of said guide sleeve, so that said sleeve may be turned from without the housing.

6. A vacuum jacket siphon for transferring low-boiling-point liquids from a supply reservoir to a working container, said siphon comprising, in combination:

means forming a siphon housing, including means for coupling the housing to such supply reservoir;

riser tube means extending from said housing beyond the coupling means and insertable into such supply reservoir to receive the contents thereof, said riser tube means including an interior riser tube surrounded by a vacuum jacket tube, the end of said riser tube means forming a valve seat;

a valve body positioned adjacent said valve seat for cooperating therewith to regulate fiow within said riser tube;

5 6 a control sleeve extending along and enclosing said References Cited by the Examiner vacuum jacket and fastened at one end to said valve UNITED STATES PATENTS body, its other end extending into said housing; 3 152 452 10/1964 Bond et a1 62 45 a rotatable guide sleeve threadedly engaged in said 5 3,255,597 6/1966 Carter housing to move longitudinally, when rotated, said OTHER REFERENCES guide sleeve being coupled to said control sleeve for controlling the position of said valve body; and Kaltetechnik, A Vacuum J acketed Siphon With Shutoff a pair of bellows in said housing for sealing off the Valve and Co pler, 1962, pages 212 213. interior of the control sleeve from the atmosphere. LLOYD L. KING, Primary Examiner. 

1. A VACUUM JACKET SIPHON FOR TRANSFERRING LOW-BOILING-POINT LIQUIDS FROM A SUPPLY RESERVOIR TO A WORKING CONTAINER, SAID SIPHON COMPRISING, IN COMBINATION: MEANS FORMING A SIPHON HOUSING, INCLUDING MEANS FOR COUPLING THE HOUSING TO SUCH SUPPLY RESERVOIR; RISER TUBE MEANS EXTENDING FROM SAID HOUSING BEYOND BOTH ENDS OF THE COUPLING MEANS, ONE END OF THE RISER TUBE MEANS BEING INSERTABLE INTO SUCH SUPPLY RESERVOIR TO RECEIVE THE CONTENTS THEREOF WHILE THE OTHER FREE END EXTENDS OUTSIDE OF THE NECK OF THE SUPPLY RESERVOIR; VALVE MEANS ON THE FREE END OF SAID RISER TUBE MEANS FOR REGULATING THE FLOW OF SAID CONTENTS THERETHROUGH; VALVE CONTROL MEANS FASTENED TO SAID VALVE MEANS AND EXTENDING ALONG THE FREE END OF THE RISER TUBE MEANS INTO THE HOUSING; AND GUIDE MEANS IN SAID HOUSING FOR ACTUATING SAID CONTROL MEANS TO CONTROL THE VALVE MEANS. 